1. Field of the Invention
The present invention relates to a wheel hub, particularly to a wheel hub to be used in a golf motor caddie.
2. Description of Related Art
Today's people spend much of their time at leisure. Especially golf has become a popular pastime. To save costs, instead of human caddies electrically driven golf motor caddies are employed to carry golf utensils. Conventional golf motor caddies are useful and cheap. However, there are still problems with the wheel hubs thereof.
A wheel hub 9 of a conventional golf motor caddie, as shown in FIGS. 3 and 4, comprises: a central axle 90; an inner tube 91; an outer tube 92, having a first end with a small opening 921 and a narrow chamber 923 and a second end with a large opening 922 and a wide chamber 924; a plastics bearing 93 around the narrow chamber 923; a second bearing 94 around the wide chamber 924; and a C-shaped washer 95 to keep the second bearing 94 concentric with the axle 90.
The outer tube 92 is connected with the plastics bearing 93, the second bearing 94 and the C-shaped washer 95 and put over the inner tube 91 to form the wheel hub 9. The wheels of the golf motor caddie each have a wheel rim 10 and a spindle 11. The wheel hub 9 is placed in a space within the spindle 11 and the wheel rim 10, ensuring that the wheel rotates smoothly. The plastics bearing 93 and the second bearing 94 surround the axle 90, which is convenient. However, for easy assembly, a comparatively large gap of about 0.15 mm width remains between the axle 90 and the inner tube 91. The width of this gap increases after prolonged use of the golf motor caddie, leading to uneven distribution of forces while the wheel rotates.